Background and Objectives Cold plasma (CP) treatment is a promising way to remove mycotoxins from cereal kernels, although its effects on nutrient contents remain unclear. This study evaluates the biochemical parameters, gelatinization properties, and fatty acid profile of Chinese hard‐white wheat flour treated with low‐pressure radio‐frequency (RF) CP (13.56 MHz, 140 Pa, helium or oxygen, 120 W, 0–180 s, 70 g sample). Findings 120 W oxygen and helium plasma respectively required 90 and 120 s treatment to remove 50% deoxynivalenol (DON) from hard‐white wheat flour samples with 1.22 μg/g DON. A General Linear Model–Univariate analysis shows that oxygen and helium plasma both significantly increased water absorption rate, conductivity, and contents of reducing sugars, amylose, soluble protein, and saturated fatty acids in wheat flours but decreased the contents of soluble amino acids, total, unsaturated, mono‐unsaturated and poly‐unsaturated fatty acids, and enthalpy of gelatinization, and kept gelatinization peak temperature. At the same treatment time, helium plasma induced a higher water absorption rate, conductivity, and contents of pentosan and sulfhydryl groups in wheat flours than oxygen plasma. Oxygen plasma induced more reductions in mono‐ and poly‐unsaturated fatty acids in wheat flours than helium plasma. Compared with the untreated samples, helium plasma increased the values of water SRC, NaHCO3 SRC, and sucrose SRC, but decreased the lactic acid SRC, suggesting that the flour functional polymers were modified by helium plasma treatment, but oxygen plasma kept these four SRC values and did not significantly alter the functional polymers in wheat flour. Conclusion The treatment with low‐pressure RF CP can increase hydrophilicity, and unsaturated fatty acid oxidation in wheat flours while kept starch gelatinization, and helium plasma can modify the flour's functional polymers. Significance and Novelty The suitable helium CP treatment (low‐pressure RF, 120 W, and 90–120 s) is a promising way to reduce the contaminants of wheat flours and improve their functional properties.

Background and objectives Rice is an important staple food that is often stored for long periods (e.g., 2 years) but is subject to aging effects that reduce quality. Therefore, a sensitive freshness detection method for long‐term paddy storage is required. Findings This study stored five varieties of Chinese paddy at 4°C, 15°C, 20°C, or 35°C for 10 months, and then analyzed their solvent retention capacity (SRC), freshness index, contents of fatty acids, amylose, protein and soluble amino acids, and their thermal and thermomechanical properties. The results show that the SRC values in water, 5% NaHCO3, 5% lactic acid, and 50% sucrose solution decreased with increases in storage temperature and duration, with no differences among the five varieties. The four SRC values were negatively correlated with an existing freshness index (D615–D690), which could not distinguish between the effects of storage temperature and duration. With the SRC values for newly harvested paddy stored at 4°C used as a reference, the mean and accumulated SRC reductions were found to increase with storage temperature and duration. A protocol for rice freshness detection was developed based on these four SRC values. Conclusion Paddy with a mean SRC reduction of ≤25% is eligible for preservation, that with a mean of 25%–30% is slightly ineligible for preservation, and that with a mean of >30% is unfit for preservation. If the sum of the four SRC reductions is ≤100%, the paddy is eligible for preservation, a sum of 100%–120% indicates that it is slightly ineligible for preservation, and a sum >120% indicates that it is unfit for preservation. Significance and novelty This novel method based on SRC values provides an improved way to assess the freshness of stored rice.

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